This disclosure relates to an aircraft auxiliary power unit assembly, which includes an inlet duct arranged at an aircraft skin. The disclosure also relates to a method of servicing the auxiliary power unit while keeping the aircraft skin in place.
Auxiliary power units (APU) are commonly used in aircraft to provide emergency power for various aircraft systems. Typically, the APU is mounted to structural members within a tail cone of the aircraft. Aircraft skin is secured to the structural members, such as the airframe, to enclose the APU. To service components of the APU, such as line replaceable units (LRUs), portions of the skin must be removed to provide sufficient access to the LRUs.
An inlet duct is typically integral with a housing of the APU. The inlet duct extends from the APU and seals against an interior surface of the aircraft skin within the cavity. The inlet duct cannot be removed until the skin is removed from the airframe.